Concavity of Von Neumann entropy
= Concavity of Von Neumann entropy
{c}
For <density operator>[density operators] $\rho_1,\rho_2$ and $0\leq p\leq1$, <Von Neumann entropy> is <concave>:
$$
S(p\rho_1+(1-p)\rho_2)\geq pS(\rho_1)+(1-p)S(\rho_2).
$$
= Concavity of Von Neumann entropy
{c}
For <density operator>[density operators] $\rho_1,\rho_2$ and $0\leq p\leq1$, <Von Neumann entropy> is <concave>:
$$
S(p\rho_1+(1-p)\rho_2)\geq pS(\rho_1)+(1-p)S(\rho_2).
$$